Abstract: An electronic device such as a watch comprises a solar cell (14) and window portions (2, 6) which is located on the solar cell (14) and through which light is applied to the solar cell (14). The solar cell (14) is divided into a plurality of divided cells such that irradiated portions (14A to 14F) of the divided cells are equal in area, in consideration of the shapes, areas, and number of the window portions (2, 6) and the number of divisions of the solar cell (14).

Abstract: An electronic device such as a watch comprises a solar cell (14) and window portions (2, 6) which is located on the solar cell (14) and through which light is applied to the solar cell (14). The solar cell (14) is divided into a plurality of divided cells such that irradiated portions (14A to 14F) of the divided cells are equal in area, in consideration of the shapes, areas, and number of the window portions (2, 6) and the number of divisions of the solar cell (14).

Abstract: An electronic timepiece has a calendar advancement device resistant to external shock and capable of achieving date correction in a short time. A date dial advancement transducer (51) is activated in response to a date dial drive signal generated by a 24-hour switch. A date advancement mechanism (a date gear train) (52) employs a Geneva wheel for stabilizing the date dial (70). A bounding restraint lever is regulated using an eccentric cam or the like provided coaxially with the Geneva wheel.

Abstract: An electronic timepiece is provided with a device for automatically adjusting month-end calendar dates capable of reading dates simply, quickly, and reliably. A date detection pattern 71 composed of reflective and non-reflective sections is formed on the rear surface of a date dial 70. When the date dial 70 rotates, a change in the boundary between the reflective part and the non-reflective part is read by a photo sensor 81, the necessary number of dates is determined by a control circuit 20 by use of a perpetual calendar circuit, driving a date dial driving mechanisms 51 and 52.

Abstract: An electronic timepiece is provided with a device for automatically adjusting month-end calendar dates capable of reading dates simply, quickly, and reliably.

Abstract: An electronic timepiece is provided with a device for automatically adjusting month-end calendar dates capable of reading dates simply, quickly, and reliably. A date detection pattern 71 composed of reflective and non-reflective sections is formed on the rear surface of a date dial 70. When the date dial 70 rotates, a change in the boundary between the reflective part and the non-reflective part is read by a photo sensor 81, the necessary number of dates is determined by a control circuit 20 by use of a perpetual calendar circuit, driving a date dial driving mechanisms 51 and 52.

Abstract: To provide an electronic watch with calendar without the need to adjust the calendar when the watch is restarted. A control mechanism 133 is provided which uses a signal from a 24-hour switch 12 which operates in synchronism with a time mechanism converter 6 as a signal for operating a date display drive converter 51 during normal watch operation, and uses a signal from a 24-hour counter which receives a signal from a time mechanism circuit 60 as a signal for operating the date display drive converter 51 at other times.